Deodorants and Antiperspirants Affects Underarm Microbiome

Deodorant has some undoubtedly positive effects. I’m pretty sure that every person reading this article has wished at least once that someone was wearing deodorant. Antiperspirant is pretty much in the same dog house, providing us with slightly more tolerable public transportation rides. But according to a study from North Carolina, deodorants and antiperspirants mess up our microbiome.

You and your microbiome

For those of you that don’t know what your microbiome is, here is a very succinct biology lesson. The microbiome is the community of microbes living in a certain environment. There is also a pan-microbiome, referring to all the microbes on Earth.

In this case, the study refers to the microbes living under our arms – on our armpits, to be more exact. Most microbes living on the surface of your skin – and there are a lot of those – are beneficial, or at least harmless.

They tend to feed on what your body excretes – and by that I mean very small stuff, like sweat, dead skin, etc. – and to fend off other microbes that want to make you their home, usually by not letting them feed and having them starve to death.

The largest part of benevolent bacteria living on a human body is Corynebacteria. They are responsible for your body odor, as they feed off the sweat you eliminate from your glands.

In the study, a team of researchers from the North Carolina Central University wanted to find out the effect of antiperspirants and deodorants on the microbiome living under your arms. And this is the beginning of the experiment.

Antiperspirant vs. deodorant vs. nothing

For the study, the team had a sample of 17 men and women, and divided them into three groups. The first group would wear antiperspirant for eight days, while the second would wear deodorant. The third group was the control group, and they would use nothing for the following eight days.

But there is slightly more to the experiment – samples of armpit bacteria were collected both at the beginning of the eight days, and during the final day; additionally, all subjects used antiperspirants after the eighth day sample, and another one was collected afterwards.

The group that didn’t use anything was found to have the highest amount of Corynebacteria, as well as the lowest number of the harmful Staphylococcaceae bacteria.

The antiperspirant group showed pretty much the same number of Staphylococcaceae as the deodorant group, but far fewer Corynebacteria than the other two groups. Meanwhile, unidentifiable bacterium were present as 10% in the control group, as 5% in the deodorant group, and as 20% in the antiperspirant group.